The game does not allow using advanced physical effects unless the computer has PhysX acceleration enabled. Therefore we only tested graphics subsystems with PhysX support. We used the PhysX High mode.
The single GeForce GTX 275 turns in the worst result as it has to do both 3D rendering and physics processing at once. The configurations with a dedicated PPU show better performance. The EVGA card, although ahead of the GeForce GTX 275 + GT 220 subsystem in terms of bottom speed, is inferior to the latter in average performance, especially at 1920x1200. Perhaps this is due to the larger amount of graphics memory available to the PPU in the GTX 275 + GT 220 configuration. We guess the latter subsystem is more appealing even though it occupies two PCI Express x16 slots. Note also that neither system can deliver a comfortable frame rate at 2560x1600. The hybrid solution with the XFX Radeon HD 5850 Black Edition as the main graphics card is very, very fast. Its performance remains at about the same level irrespective of the display resolution. It’s a shame that this tandem cannot boast high stability. Otherwise, it would be just perfect.
Darkest of Days
We used the integrated benchmark at highest settings of graphics quality and physical effects.
The picture looks similar to what we saw in Cryostasis. The dedicated PPU ensures a hefty performance gain that may make the difference between whether the game is comfortable to play or not. When PhysX acceleration is turned off, the game is reduced to a slideshow. For some reason, the use of a standalone GeForce GT 220 card as a physics accelerator does not improve the performance much except for 2560x1600 where the GeForce GTX 275 + GT 220 overtake the EVGA solution. This behavior is not what we see in other PhysX-supporting games. Perhaps Darkest of Days does not utilize the PPU’s resources effectively or the EVGA GeForce GTX 275 CO-OP PhysX is faster due to the higher frequency of its PPU's computing subunits.
Users of AMD cards have to forget about this game altogether or use the PhysX mod patch. Although less stable, the hybrid tandem with the XFX Radeon HD 5850 Black Edition delivers an acceptable frame rate, although cannot overtake the EVGA GeForce GTX 275 CO-OP PhysX. We are still wondering at Nvidia’s stubborn desire to keep PhysX all to themselves. Being exclusive, the technology can never really take off.
The EVGA GeForce GTX 275 CO-OP PhysX has lower bottom speed than the ordinary GeForce GTX 275.
Like in the majority of games, the PhysX coprocessor is not needed here as is indicated by the results of the hybrid tandem built out of the XFX and the GeForce GT 220 cards. The reduction of the shader domain frequency affects the performance of the EVGA card even though its frame rate is high even at 2560x1600.